EP2723991B1 - Blade arrangement - Google Patents

Description

The invention relates to a blade arrangement according to the preamble of claim 1.

Such blade arrangements are well known from the extensive existing state of the art, see for example the patent application DE 1 085 643 , The known blade arrangements are used both for rows of blades and for blade rows of compressors, wherein in a blade carrier, a circumferential groove for receiving all the blades of the series is provided. The attachment of the blades in the circumferential groove takes place with the aid of a hammer-shaped or dovetail-like positive connection by correspondingly designed blade roots engage behind projections protruding from the side walls of the retaining groove. In order to bring about a backlash-free, low-wear and reliable clamping of the blades in the retaining groove, it is known to use subfloors in the form of feather keys, spring elements in the form of a spiral spring or a longitudinally and transversely slotted clamping sleeve between the underside of the blade root and groove base. This can be in the radial direction existing assembly and manufacturing games compensate between the blade and groove, which allows easy production and assembly. The problem is that the games in the radial direction can lead to difficulties in ensuring the tolerances in Nutumfangsrichtung. Therefore, it is known that for adjustment of the radial gap between the blade tip and one of these immediately opposite channel boundary, the profile ends are ground or made by turning to measure, during which the blades mounted in the groove are pressed outwards. Apart from that, there is often the problem to achieve a simple assembly and disassembly of blades and the substructures with low production costs.

The object of the invention is therefore to provide a blade assembly in which a durable and reliable and secure fastening of the blades in the circumferential groove is ensured with simple assembly and disassembly.

The object is achieved with a blade arrangement according to the features of claim 1. Advantageous embodiments of the invention are specified in the subclaims, which can be combined with one another in any desired manner.

According to the invention, it is provided that each element is plate-shaped, has at least one bead arranged below the blade in the projection of the blade blade groove for pressing the blade in the groove and in the longitudinal direction of the retaining only partially covered by him pressed blade root. With the aid of the element according to the invention, it is possible that this has a particularly suitable shape, which allows a locally resilient substructure and at another local point a rigid-looking substructure. On the one hand, the element is particularly easy to manufacture and, on the other hand, it is particularly easy to assemble and disassemble. The stiffening effect is generated by a bead or several beads. The ease of assembly and disassembly is achieved in that in the longitudinal direction of the retaining the element in question is only partially covered by the pressed by him blade root. Thus, always a section of the element stands out, which is particularly easy to reach for a disassembly tool. Furthermore, the plate-shaped geometry of the element allows a space-saving design and blade arrangement.

Furthermore, the inventive solution includes that in the holding between each two blades a one-piece or multi-piece spacer is inserted, which is pressed by the not covered by the blade root part of the element to the projections. In this case exist in identical Number of blades, intermediate pieces and elements, wherein the elements have a longitudinal extent which is equal to the longitudinal extent of blade root and intermediate piece. The assembly of the elements is offset with respect to spacers and blades, so that the element - viewed in the longitudinal direction of the retaining - extends completely under the blade root and each partially extends below the two, the blade root adjacent spacers. Thus, each intermediate piece of two elements is pressed against the projections of the retaining groove.

Preferably, the elements are designed such that the respective intermediate pieces are pressed against the projections with less force than the pressed by the respective element to the projections blade root. In particular, different stiffnesses of the element can be used particularly advantageously for different requirements. For the assembly of the intermediate pieces namely a lower spring force of the element is desirable and not needed, since in operation also do not attack high forces on the intermediate piece. In contrast, the blades clamped in the blade carrier are exposed to flow forces during operation. This requires a more reliable attachment of the blades to the blade carrier, which requires a larger contact force. The higher contact pressure is achieved by the locally higher rigidity of the element. This will be caused by the bead (s) arranged in the element.

In the case of a stiffer substructure of the blade, it is advantageously possible to use differently acting functional principles for assembly and subsequent operation. On the one hand, the local material plasticization of the bead is provided to compensate for manufacturing tolerances during assembly. On the other hand, a use of the residual elasticity is provided to then absorb the operating forces. For this purpose, a material is advantageously used for the element, which is characterized by a relatively high ratio of the index for maximum tensile strength (Rmax) to the yield strength (RP0.2) (Index Rmax / Rp0.2> 1.5), whereby with material choice the yield strength at the same time still sufficiently large enough for the operating force must be.

• R1 > 1,5S,
• 3*R2 > R1 < 0,7R2 und
• 10b bis 1,7b > a.

The locally more rigid region of the element is preferably designed as a bead. Particularly advantageous is the design of the bead in a manner that results in a kinked curve in the force-displacement relationship. As a result, over a wide range, a residual elasticity to accommodate the operating forces is ensured. This can be achieved with a first bead geometry, in which the element has a wall thickness S and the bead has in cross section a bead width b and two convex sections with a radius R2 and a concave section with a radius R1 with a chord length A arranged therebetween applies:

• R1> 1.5S,
• 3 * R2> R1 <0.7R2 and
• 10b to 1.7b> a.

A second bead geometry with similar properties is achieved when R1> 5S, 3 * R2> R1 and a '<0.9b.

A third bead geometry as a combination of the first two bead geometries with similar properties leads to a double bead called a double bead, which has a further enlarged elastic range.

Preferably, the beads are located in the element so that they are arranged in the projection of the blade leaf groove bottom direction below the blade. In other words, since the elements are always offset along the circumferential groove to the blades, the beads are arranged in principle in the interior of the element or at its edge. This allows easy assembly and disassembly of the elements.

More preferably, the element has at least one opening in its area not covered by the blade root. In this opening can engage a disassembly hook or tool to disassemble it from its operating position.

A simple mountability of the element can be achieved if a groove extending along the retaining groove is located as a disassembly groove in the groove bottom of the retaining groove or in the blade root underside. During disassembly, a slide hammer can be comparatively easily attached there and during assembly, the insertion / compression of the element between the blade and the groove is simplified by means of a plunger.

The element expediently has an outer contour in the projection of the blade leaf in the direction of the groove bottom (radial viewing axis), which is substantially rectangular. In this projection, the element in question is only half covered by the blade pressed by it. Such contoured elements are particularly inexpensive and easy to produce.

Particularly advantageous is the embodiment in which at least one longitudinal edge of the element is angled, which bears biased against the correspondingly shaped blade roots. If intermediate pieces are used in the blade arrangement, the angled longitudinal edges can also be prestressed against the correspondingly shaped intermediate pieces. This embodiment makes it possible that the blades are not aligned solely on the basis of the groove geometry and the Schaufelfußgeometrie, but also on the basis of the respective neighboring component - blade or spacer - align. This feature serves to advantageously reduce contact wear.

Further advantageously, the element on at least one edge at least one further bead for local reinforcement and for guiding the element in a guide groove. This further bead on the edge, preferably the transverse edge, can simplify the assembly, because at the local stiffening a plunger for driving / pushing the element between the blade root underside and groove base can be applied without the element during subsequent driving, the element bends locally.

Particularly preferred is the embodiment in which the bead is designed as an inner bead, which is located in an at least partially surrounding, outer bead. This embodiment, also referred to as a double bead, allows a further enlargement of the elastic region of the element. Likewise, the use of 3-fold beads or even n-fold beads is conceivable in which a corresponding number of beads from the inside to the outside is virtually stacked or arranged hierarchically.

Particularly preferred is the embodiment in which the blade assembly is used in an axially flow-through compressor of a gas turbine, either for a blade ring and / or for a vane ring. This ensures a reliable, safe and particularly efficient operation of the gas turbine, since with this embodiment, the radial gaps between the blade tips and the opposite channel wall of the flow channel of the compressor can be made particularly small.

FIG 1

einen Längsteilschnitt durch eine Gasturbine,

FIG 2

die Draufsicht auf einen Ausschnitt einer Schaufelanordnung gemäß einer ersten Ausgestaltung,

FIG 3

einen Querschnitt durch die Schaufelanordnung gemäß FIG 2 gemäß Schnittlinie III-III,

FIG 4

den Längsschnitt durch den Ausschnitt der Schaufelanordnung gemäß FIG 2 gemäß Schnittlinie IV-IV,

FIG 5, FIG 6

die Querschnitte durch eine Schaufelanordnung analog zur Schnittlinie IV-IV für eine zweite und dritte Ausgestaltung,

FIG 7

eine Draufsicht auf einen Abschnitt einer Schaufelanordnung gemäß einer vierten Ausgestaltung (ohne Zwischenstücke),

FIG 8, FIG 9

zwei Varianten der vierten Ausgestaltung gemäß FIG 7 im Querschnitt gemäß Schnittlinie III-III,

FIG 10

eine Draufsicht auf einen Abschnitt einer Schaufelanordnung gemäß einer fünften Ausgestaltung (ohne Zwischenstücke),

FIG 11, FIG 12

zwei Varianten der fünften Ausgestaltung gemäß FIG 7 im Querschnitt gemäß Schnittlinie III-III,

FIG 13

ein Kraft-Elastizitäts-Diagramm,

FIG 14, FIG

15 den Querschnitt durch ein Element mit unterschiedlichen Geometrien von Sicken und

FIG 16

den Querschnitt durch eine Sickengeometrie in Form einer Doppelsicke.

The invention will be explained in more detail in the following description of the figures with reference to several embodiments, which do not limit the invention. In this case, further features and other advantages are given. Show it:

FIG. 1

a partial longitudinal section through a gas turbine,

FIG. 2

the top view of a section of a blade assembly according to a first embodiment,

FIG. 3

a cross section through the blade assembly according to FIG. 2 according to section line III-III,

FIG. 4

the longitudinal section through the cutout of the blade assembly according to FIG. 2 according to section line IV-IV,

FIG. 5, FIG. 6

the cross sections through a blade arrangement analogous to the section line IV-IV for a second and third embodiment,

FIG. 7

a plan view of a portion of a blade assembly according to a fourth embodiment (without spacers),

8, FIG. 9

two variants of the fourth embodiment according to FIG. 7 in cross-section according to section line III-III,

FIG. 10

a plan view of a portion of a blade assembly according to a fifth embodiment (without spacers),

FIG. 11, FIG. 12

two variants of the fifth embodiment according to FIG. 7 in cross-section according to section line III-III,

FIG. 13

a force-elasticity diagram,

FIG. 14, FIG

15 shows the cross section through an element with different geometries of beads and

FIG. 16

the cross section through a bead geometry in the form of a double bead.

In the figures, identical features are provided with the same reference numerals.

FIG. 1 shows a stationary gas turbine 10 in a longitudinal partial section. The gas turbine 10 has inside a by one Rotation axis 12 rotatably mounted rotor 14, which is also referred to as a turbine runner. Along the rotor 14 follow one another an intake housing 16, an axial turbocharger 18, a toroidal annular combustion chamber 20 with a plurality of rotationally symmetrically arranged burners 22, a turbine unit 24 and an exhaust housing 26.

The Axialturboverdichter 18 includes a ring-shaped compressor duct with cascading successively compressor stages of blade and Leitschaufelkränzen. The rotor blades 14 arranged on the blades 27 lie with their free-ending blade tips 29 of an outer channel wall 42 of the compressor passage opposite. Also protrude vanes 25 which are secured to the outer duct wall 42 or to a Verdichterleitschaufelträger. The compressor duct discharges via a compressor outlet diffuser 36 in a plenum 38. The annular combustion chamber 20 is provided with its combustion chamber 28, which communicates with an annular hot gas duct 30 of the turbine unit 24. In the turbine unit 24 four successive turbine stages 32 are arranged. On the rotor 14, a generator or a working machine (each not shown) is coupled.

During operation of the gas turbine 10, the axial turbocharger 18 draws in ambient air 34 through the intake housing 16 as a medium to be compressed and compresses it. The compressed air is guided through the compressor outlet diffuser 36 into the plenum 38, from where it flows into the burner 22. Fuel also passes into the combustion space 28 via the burners 22. There, the fuel is burned to a hot gas M with the addition of the compressed air. The hot gas M then flows into the hot gas duct 30, where it relaxes to perform work on the turbine blades of the turbine unit 24. The energy released during this time is absorbed by the rotor 14 and used on the one hand to drive the axial turbocharger 18 and on the other hand to drive a working machine or electric generator.

The FIG. 2 shows a plan view of a portion of a blade assembly 40, in which only two blades 25, 27 are schematically illustrated with an intermediate piece 44 located therebetween and two elements 46 disposed thereunder. The blades 25, 27 comprise a schematically indicated blade 48 as well as a blade root 50. The plan view takes place in the direction of the radial direction of the gas turbine 10, ie from the blade towards the blade root 50 FIG. 2 not shown is the blade carrier and a holding groove arranged in the carrier. The elements 46 have a rectangular outer contour and are plate-shaped. Colloquially, they are also referred to as sheet-shaped. In the first embodiment ( FIG. 2 ) are the blade roots 50 and the blades 25, 27 of the blade assembly with respect to a longitudinal extent of the retaining groove or a circumferential direction U arranged obliquely. This employment is typical for blades.

Each element 46 has two beads 52 and two openings 54, respectively. The elements 46 are in the circumferential direction U as long as the blade root 50 and spacer 44 together. However, the elements 46 are arranged centrally below the respective blade 25, 27, so that two adjacent elements 46 each end centrally with their opposite ends below the intermediate pieces 44.

FIG. 3 shows the cross section along section line III-III through the blade root 50 of the blade 25, 27 and a blade carrier 56. The blade is in FIG. 3 (and also in the FIGS. 5, 6 . 8, 9 . 11 and 12 ) not shown. In the blade carrier 56, a retaining groove 58 extends, in which the blades 25, 27, in detail the blade roots 50 of the blades 25, 27, are inserted in a form-fitting manner. To form the form-fit, the side walls 60 of the retaining grooves 58 have longitudinally extending projections 62 for forming undercuts 64. Correspondingly executed, hammer-shaped foot regions 66 engage in the undercut 64.

Between a blade root bottom 68 and a groove bottom 70 of the retaining groove 58, the element 46 is braced. In addition, a further, along the retaining groove 58 extending disassembly groove 72 is provided in the groove bottom 70. The further groove 72 serves for the access of a disassembly tool, for example a slide hammer.

The wall thickness S of the element 46 ( FIG. 14 ) is less than the gap between the blade root bottom 68 and groove bottom 70. The beads 52 produced in the element 46 by deep drawing or by pressing increase the height H of the element 46 beyond the gap, so that the blade root 50 is pressed against the projections 62. This leads to a clearly defined position of the blades 25, 27 in the retaining groove 58.

FIG. 4 shows the longitudinal section through the embodiment according to FIG. 2 along the section line IV-IV. In the in the FIGS. 2, 3 and 4 illustrated embodiment of the blade assembly 40 is a section of a blade ring of a compressor 12 of the gas turbine 10. Accordingly, the blade carrier 56 is formed by a rotor disk and the blades 25, 27 formed as blades.

The elements 46 are substantially planar and thus do not follow the curvature of the retaining groove 58. As a result, the elements 46 press with their central region in which the beads 52 are arranged with greater force blade root lower side 68 and groove bottom 70 apart. The adjacent to the transverse edges 82 portions of the element 46 are due to the planar configuration of the elements 46 and the curved retaining groove 58 then with less force resiliently against the undersides of the intermediate pieces 44. Consequently, the element 46 presses the intermediate pieces 44 and the blades 25, 27 against the projections 62 of the retaining groove 58 due to locally different stiffnesses with forces of different magnitude.

A second embodiment of a blade arrangement 40 is shown in FIG FIG. 5 shown. FIG. 5 shows essentially the cross section according to FIG. 3 , Here are in FIG. 5 to FIG. 3 identical features provided with the identical reference numerals. To the description of FIG. 5 is largely based on the description of the FIG. 3 directed. According to the second embodiment, however, the longitudinal edges 74 of the element 46 are bent to the groove opening of the retaining groove 58 out. The bent longitudinal edges 74 (see. FIG. 2 ) are preloaded on blade bottom 76 disposed chamfered on. Since the intermediate pieces 44 are formed in a manner analogous to the blade roots 50 of the blades 25, 27, the regions of the longitudinal edges 74 of the element 46 located below the intermediate piece 44 are biased against corresponding chamfers. The bent longitudinal edges 74 of the element 46 and the biased contact of the elements 46 on the blade roots 50 and spacers 44, a frictional coupling of the adjacent components - blade root 50 and spacer 44 - caused, which improves their alignment and reduces contact wear between the components.

A third embodiment of a blade arrangement 40 is shown in FIG FIG. 6 shown schematically. Also FIG. 6 shows largely the same cross-section as FIG. 3 , so in FIG. 6 to FIG. 3 identical features are provided with the same reference numerals. In contrast to the embodiment according to FIG. 3 has the third embodiment according to FIG. 6 at the blade root lower side 68 a comparatively wide, but provided only with a small depth, in the longitudinal direction of the retaining groove 58 extending groove 78. The groove 78 serves to receive the element 46, so that the groove depth of the groove 78 substantially corresponds to the wall thickness S of the element 46. The longitudinal edges 74 of the element 46 (see. FIG. 2 ) abut against the inclined side walls of the groove 78. In the same extent as the blade root 50, a groove 78 arranged on the underside thereof is also provided in the intermediate pieces 44 according to the third embodiment, so that the longitudinal edges 74 of the element 46 also on the side walls of the groove 44 arranged on the intermediate piece 78 are present. By the simultaneous contact of the elements 46 on blade 25, 27 and intermediate piece 44, a coupling of the adjacent blade ring components is brought about, which reduces wear, in particular contact wear. Both in the second embodiment according to FIG. 5 and the third embodiment according to FIG. 6 In the case of the blade arrangement 40 according to the invention, the blades are designed as moving blades 27.

The FIGS. 8 and 9 show in an analogous manner to the cross section according to FIG. 3 a cross section through a blade assembly 40 according to a fourth embodiment. In contrast to the aforementioned embodiments, the in FIGS. 7, 8 and 9 arrangements shown designed as vane rings and not as blade rings. As a result, the cross-sectional contours of the retaining groove 58 and the blade root 50 differ only slightly. Another difference from the previously described embodiments is that no intermediate pieces 44 are provided between adjacent guide vanes 25. Accordingly, the blades 25 lie as shown in the illustration FIG. 7 shown flat and without employment of the blade roots 50 together. In this case, the elements 46 are each arranged in half below a pair of adjacent blades 25. It follows that the stiffening beads 52 are not located in the interior of the element 46, but at two opposite transverse edges 82 of the elements 46. Otherwise, the first variant of the fourth embodiment according to FIG. 8 constructed in an analogous manner as the second embodiment according to FIG. 5 with the angled longitudinal edges 74 of the element 46. A second variant of the fourth embodiment, shown in FIG FIG. 9 , structurally corresponds essentially to the third embodiment FIG. 6 in which the element 46 is largely sunk in a groove 78 disposed on the blade root lower side 68.

A fifth embodiment of the blade assembly 40 is in a plan view according to FIG. 10 shown, to the two variants, a first in cross section in FIG. 11 and a second in the Cross section in FIG. 12 are shown. In the FIG. 5 The fifth embodiment shown is essentially based on the FIG. 2 illustrated first embodiment. However, in addition to the beads 52 arranged in the inner region of the element 46, further beads 86 are provided at the transverse edges 82 - in a manner analogous to that in FIGS FIG. 7 shown fourth embodiment - provided. By using the further beads 86 on the edge, bending or buckling of the element 46 can be reliably avoided when the element 46 is driven in between the blade footer bottom 68 and groove base 70. At the same time, the further beads 86 either engage in the dismantling groove 72 (FIG. FIG. 11 ) or in a blade bottom side groove 78 ( FIG. 12 ) for aligning or guiding the elements 46.

The FIGS. 14 and 15 each show an embodiment of the element 46 in cross section according to the section line III-III FIG. 2 , Unlike the in FIG. 2 shown element 46 are in the FIGS. 14, 15 only one bead 52 and not two beads 52 shown. Each bead 52 includes two convexly bent portions X and a concave portion V interposed therebetween. The convex portions X each have a radius R2 and the concave portions V have a radius R1. The concave portion V also has a chord length a, wherein the bead 52 includes a bead width b. In order to obtain the bead 52 itself with a range of plastic deformation for higher loading force and higher spring rate as well as for a range with elastic deformation with low spring rate, two embodiments of the element are proposed. The first embodiment is achieved when
R1> 1.5 * S, 3 * R2>R1> 0.7 * R2 and 10 * b to 1.7 * b> a. By way of example, the parameters may have the following dimensions: R1 = 2 mm; R2 = 2 mm; S = 1 mm; a = 3.5 mm and b = 10 mm.

• R1 > 5*S,
• 3*R2 < R1 und
• a < 0,9*b ist.

The second embodiment of an element 46 provides that

• R1> 5 * S,
• 3 * R2 <R1 and
• a <0.9 * b.

• R1 = 20 mm; R2 = 2 mm; S = 1 mm; a = 6 mm und b = 10 mm.

By way of example, the parameters may have the following dimensions:

• R1 = 20 mm; R2 = 2 mm; S = 1 mm; a = 6 mm and b = 10 mm.

With the aid of the illustrated embodiment, it is possible for the portion V to represent the area of plastic deformation with the higher loading force and higher spring rate and the portions X the areas for the elastic deformation with low spring rate, which also FIG. 13 represents.

• R20 = 20 mm; R1.2 = 2 mm; R2 = 2 mm; ba = 11 mm, aa = bi = 7,4 mm, R3 = 2 mm und ai = 3,2 mm.

FIG. 16 shows the cross section through a special bead geometry. The special bead geometry is a multiple bead 55 in which an inner bead 55i is surrounded by one or more beads 55a. The beads 55i, 55a of the multiple bead 55 are arranged in a quasi-stacked or hierarchical manner with a common center M. At the in FIG. 16 shown Mehrfachsicke 55 is a 2-fold bead, also called double bead. Double bead means that a second (then inner) bead 55i is located in a principally concave section Va of a first (then outer) bead 55a. This bead combination has over the aforementioned geometries, which can be referred to as i-fold beads, a further increased elasticity, whereby larger manufacturing tolerances for the blade roots 50, possibly intermediate pieces 44 and retaining groove 58 can be allowed. Dimensions for the bead geometry after FIG. 16 are then, for example:

• R20 = 20 mm; R1.2 = 2 mm; R2 = 2 mm; ba = 11 mm, aa = bi = 7.4 mm, R3 = 2 mm and ai = 3.2 mm.

Overall, the invention relates to a blade assembly 40 having a blade carrier 56 and a retaining groove 58 disposed therein, which has on its side walls 60 longitudinally extending projections 62 for forming undercuts 64, and in which a number of blades 25, 27 for forming a blade ring one Turbomachine used is, wherein each blade 25, 27 next to a blade 48 for fastening a hammer-shaped, engaging in the undercuts 64 blade root 50 and is pressed by between a blade root bottom 68 and a groove bottom 70 of the retaining groove 58 disposed element 46 to the projections 62. In order to provide a particularly safe, reliable, durable and low-wear attachment, which allows a particularly simple assembly and disassembly is provided that each element 46 is plate-shaped, in the projection of the airfoil 48 towards the groove bottom 70 at least one below the airfoil 48 arranged bead 52 has for pressing and in the longitudinal direction of the retaining groove 58 is only partially covered by the pressed him blade root 50.

Claims (13)

1. Blade arrangement (40), with a number of blades (25, 27), a number of plate-shaped elements (46), a number of intermediate pieces (44), a blade carrier (56) and with a holding groove (58) which is arranged therein and which has on its side walls (60) longitudinally extending projections (62) for the formation of undercuts (64), and in which the number of blades (25, 27) for forming a blade ring of a turbomachine are inserted, each blade (25, 27) having in addition to an airfoil (48), for fastening, a blade root (50) engaging into the undercuts (64) and being pressed against the projections (62) by in each case a plate-shaped element (46) arranged between a blade root underside (68) and a groove bottom (70) of the holding groove (58) and having at least one bead (52, 55), characterized in that each element (46) is covered in the longitudinal direction of the holding groove (58) only partially by the blade root (50) pressed down by said element and in that an intermediate piece (44) is inserted in the holding groove (58) between two blades (25, 27) and is pressed against the projections (62) by that part of the element (46) which is not covered by the blade root (50).
2. Blade arrangement (40) according to Claim 1, in which the element (46) presses the respective intermediate piece (44) against the projections (62) with lower force than it presses the respective blade root (50).
3. Blade arrangement (40) according to Claim 2, in which that region of the element (46) which is covered by the blade root (50) is designed to be partially more rigid than the remaining part of the respective element (46).
4. Blade arrangement (40) according to one of the preceding claims, in which the element (46) has, in its region not covered by the respective blade root (50), at least one orifice for demounting.
5. Blade arrangement (40) according to one of the preceding claims, in which a longitudinally extending groove (72, 78) is arranged in the groove bottom (70) of the holding groove (58) or in the blade root underside (68).
6. Blade arrangement (40) according to one of the preceding claims, in which the element (46) has, in a projection, an outer contour which is essentially rectangular.
7. Blade arrangement (40) according to Claim 6, in which at least one longitudinal edge (74) of the element (46) is angled and bears, prestressed, against the blade roots (50) shaped correspondingly to it.
8. Blade arrangement (40) according to Claim 7, in which at least one longitudinal edge (74) of the element (46) is angled and bears, prestressed, against the blade root (50) shaped correspondingly to it and against the intermediate piece (44) shaped correspondingly to it.
9. Blade arrangement (40) according to Claim 6 or 7, in which at least one further bead (86) is provided at at least one margin of the element (46).
10. Blade arrangement (40) according to one of the preceding claims, in which the element (46) has a wall thickness (s) and the bead (52, 55, 86) has in cross section a bead width (b) and also two convex portions (X) with a radius (R2) and a concave portion (V), arranged between them, with a radius (R1), with a chord length (a), to which the following applies:

    R1 > 1.5*s,

    3*R2 > R1 < 0.7*R2 and

    10*b to 1.7*b > a

    or

    R1 > 5*s,

    3*R2 < R1 and

    a < 0.9*b.
11. Blade arrangement (40) according to one of Claims 1 to 10, in which the bead is configured as a multiple bead.
12. Blade arrangement (40) according to Claim 11, in which the multiple bead (55) comprises an inner bead (55i) which is established in at least one outer bead (55a) at least partially surrounding the latter.
13. Axial compressor for a gas turbine (10), with a moving blade ring and/or a guide blade ring designed as a blade arrangement (40) according to one of the preceding claims.

Images